This invention relates to laminated products or constructions and their method of making, and, in particular, relates to trim strips or moldings made therefrom which are adapted for attachment to automobiles or other vehicles for decorative and protective purposes. Trim strips or moldings made in accordance with this invention have an attractive appearance and function satisfactorily yet are light in weight and, hence, can be employed instead of heavier trim strips or moldings to reduce the weight of vehicle to which they are attached. Reduced weight, of course, increases the fuel efficiency of a vehicle and promotes energy conservation. As used hereinafter, the term "molding" will be used with the understanding that it broadly includes molding strips, trim strips and the like.
Automotive moldings are well known and have been used for many years to improve the appearance and protect the bodies of automotive vehicles. In recent years there has been increasing use of plastic materials in the manufacture of moldings. While such moldings offer satisfactory performance and appearance characteristics, there is a continuing need to reduce the weight of vehicles for increased fuel efficiency. Accordingly, it would be desirable to develop moldings which are light in weight and yet have satisfactory performance characteristics for long term use and protection of the vehicle while also presenting an attractive appearance.
One class of materials which is relatively lightweight and which can be extruded into suitable shapes for moldings is the class of thermoplastic elastomers. Such materials can be, for example, about 25% lighter in weight than the polyvinyl chloride which is now commonly used in moldings. Furthermore, thermoplastic elastomer materials can have excellent physical properties for use in moldings such as good processability, low shrinkage, good high and low temperature properties, and good weathering. Unfortunately, the mar resistance of thermoplastic elastomer materials is generally poor and pigmenting such materials to obtain a variety of colors can be difficult.
It would be desirable to have a molding largely comprising lightweight thermoplastic elastomer material but which has excellent mar resistance and could be easily pigmented. In addition, it would be desirable if such molding could optionally incorporate a metallic appearing decorative strip. A molding having a thermoplastic elastomer body with a layer of extruded polyvinyl chloride or ionomer resin laminated thereon has advantages of the thermoplastic elastomer material yet also has good mar resistance and a surface layer which can be easily pigmented. However, it has been found to be difficult to laminate such dissimilar layers using the usual extrusion techniques.
In accordance with the present invention, a laminate construction of an extruded thermoplastic elastomer body and a layer of dissimilar extruded plastic is provided by interposing a tie sheet therebetween, said tie sheet comprising a laminate of a first layer comprising a material compatible with the thermoplastic elastomer body and a second layer comprising a material compatible with the layer of dissimilar extruded plastic. By the term "compatible" it is meant that the one material will bond to the other material using conventional extrusion lamination techniques involving heat.